Pointing devices are one of the channels of communication developed for human interaction with a computer. As is well known in the art, pointing devices, among other things, help the computer operator control the movement of a cursor on a computer screen and to access and obtain various results from a computer depending upon the software program being used.
Prior pointing devices include the mouse, track ball and joy stick. These devices require removal of the operators hands from a keyboard in order to access and operate them. This results in distraction, loss of time, and the need for space adjacent to the keyboard for their operation.
A pointing device that can be operated from the typing position of a keyboard and thus avoids loss of time and distraction is described in the article "Force-to-Motion Functions for Pointing", by Joseph D. Rutledge and Ted Selker from Human-Computer Interact '90, North Holland Publishing, 1990, which is incorporated herein by reference. According to this article, a pointing stick and associated sensor assembly are mounted on the sub-key surface of a keyboard such that the stick protrudes between and above the "G" and "H" key caps. These key caps are relieved at their bases to accommodate the pointing stick. The top of the pointing stick " . . . is rounded to provide a comfortable fingertip grip. To provide mouse button signals, two microswitches and operating buttons are mounted nearly flush, just below the space bar, convenient to the thumbs", Human-Computer Interact '90, supra page 702. Since the pointing device described in this article can be operated from a typing position as part of the act of touch typing, it avoids the problems inherent in using a separate mouse, track ball, or joy stick.
An important characteristic of any new pointing device is its adaptability for use on existing computer systems. With the recent proliferation of personal computers for home, business and portable use, the success of a new pointing device is dependent upon its ability to be retrofitted in an economical, easy and efficient manner into existing computer systems.